In the Navy: The Role of Advanced Sea Mines in the Future

When it comes to War, the old adage that the best defense is a good attack rings true. Nowhere is this more the case than in naval warfare, where initiative can make the difference between victory and defeat. As an integral part of naval warMine warfare – both mine defense and mine laying or “offensive” mine war – will continue to affect naval operations.

However, the latter of these sub-disciplines – the “other” mine warfare, as Admiral James Winnefeld Jr. call it – has often been lacking in mine warfare discussions. But as defense strategists claim that naval mines will play a role in future conflicts, particularly a war over Taiwan, this critical if unspectacular aspect of naval operations is receiving increasing attention.

From the Revolutionary War to the present day, offensive mining has been a significant factor in naval warfare, sending ships and sailors to the bottom of the ocean, causing enemies to alter or halt operations, or even forcing belligerents to the negotiating table. Mines are cheap, easy to deploy, and capable of tactical, operational, and strategic effects. Although they are very destructive, they can also be very disruptive; The mere presence of mines can hamper merchant shipping, shake global markets, or paralyze naval operations. And they don’t need to be further developed to have far-reaching effects, as we recently saw in the Black Sea, where simple, Soviet-era contact mines have threatened grain shipments and possibly repelled a Russian amphibious assault on Odessa.

Estimates of stockpiles of naval mines vary, but Russia is said to have a quarter of a million, with 80,000 for China, 50,000 for North Korea and between 3,000 and 6,000 for Iran. China has shown a particular interest in offensive mining and can have up to thirty different variants in its inventory, including encapsulated torpedo mines and rocket-powered ascending mines.

The United States is in stark contrast to this. The Navy’s mine inventory currently has only two types of mines – the quick strike and the Submarine Launched Mobile Mine (SLMM) – while two other models, the Clandestine Delivered Mine (CDM) and the Hammerhead encapsulated torpedo mine, are in development. Quickstrike are air-dropped shallow water mines that are actually 500, 1000 and 2000 pound general purpose “dumb” bombs equipped with Target Devices (TDDs). SLMMs are essentially heavy torpedoes that fly to a pre-programmed waypoint, sink to the seabed, and lie in wait like a regular ground mine. The status of the SLMM inventory is unclear, but an improved version called MEDUSA (Mining Expendable Delivery Unmanned Submarine Asset), which the Navy actually refers to as a medium-class UUV, is under development.

Little is known about the CDM, which has been under development for more than five years. Images circulating suggest it is a standard ground mine, while budget documents indicate it is capable of acoustic communication to allow for remote command and control. The CDM has been tested with the Navy’s Large Displacement UUV (LDUUV), Snakehead, and could also be deployed by the Navy, according to budget documents Orca Extra Large UUV (XLUUV).

Sailors assigned to the Los Angeles-class fast attack submarine USS Annapolis (SSN 760) load a MK 67 submarine-launched mobile mine (SLMM) on Annapolis May 4. Annapolis will conduct naval operations in the U.S. 7th Fleet area of ​​operations maintaining a secure and open Indo-Pacific. (US Navy photo by Mass Communication Specialist 2nd Class Zachary Groman).

The Hammerhead is actually a throwback to a Cold War era weapon – the CAPTOR (EnCAPsulated TORpedo) mine. It is a deep-sea anti-submarine mine capable of detecting, classifying, locating and attacking enemy submarines with a light Mk-54 torpedo. Unlike Quickstrike or CDM, Hammerhead is specifically designed for covert use on a single platform – the Orca XLUUV. Given the technological complexities of unmanned minelaying, as well as Orca’s production delays and cost overruns, it is likely that the Hammerhead will be fully tested and put into production before the Orca is ready to join the fleet. Whether other Hammerhead variants are in the works that would allow the use of airborne, surface, or manned underwater platforms is unknown. Advanced minelaying isn’t just for well-capitalized major powers. Recent commercial innovations are making offensive mining accessible to seafaring nations looking for an affordable, viable sea-denial capability in the face of growing threats from Russia and China. For example, the Italian company RMV Italia, a division of the German car and weapons manufacturer Rheinmetall, markets the Murena and Asteria ground mines and is rumored to be a possible future supplier to the Royal Australian Navy as Canberra seeks to fend off Chinese maritime aggression. Finnish company DA-Group produces an advanced ground mine, the Turso MM20, which can be fitted with a range of sensors and operates at depths from 10 to 200 meters.

DA group also sells a modular minelaying system called Sumico, which is essentially a 20-foot shipping container that allows twelve mines to be deployed from any ship. Another Finnish company Forced Defense (Part of Forcit Group) markets the Blocker Bottom Influence Mine which can operate at depths of up to 200 meters for two years. (In 2021, Estonia received blocker mines to bolster its coastal defense capabilities against an expansionist Russia.) And Danish company SH Defense is marketing a containerized minelaying system as part of its Cube series of modular defense payloads. Each container can hold between twenty and fifty mines, which can be deployed at a rate of two to four per minute. (In February of this year, Forcit, DA-Group and SH Defense joined forces and signed a letter of intent to jointly develop and commercialize a fully integrated, modular mine warfare system.)

But even as sensor, communications, and operational capabilities advance, sea mines remain what they have been for over a century – weapons that wait. Once deployed, they remain in place, awaiting the required sensor inputs that will trigger their destructive payload. But that is about to change – dramatically. A quiet, slow convergence of mines, torpedoes, and UUVs has been underway for over half a century, beginning with the development of the encapsulated torpedo mine during the Cold War. Although its modern descendant, the Hammerhead, now has a high-density energy source, more sophisticated sensors, algorithmic processing, and the ability to communicate, it still remains connected to the sea floor. What if the Mk-54 liquid-fuel propulsion system was replaced with a high-density, battery-powered system and turned it into a loitering, armed UUV? Such a weapon already exists in the form of battery-powered torpedoes like the F21 (which was inspired by the Naval Group’s D19 UUV), the Black Shark, the Sea Hake, the MU90 and the Saab Lightweight Torpedo (SLWT), all of which have 50-speeds can reach knots and have a lifespan of almost an hour. Endurance is perhaps the greatest challenge in developing permanent, mobile minefields. Last year, Chinese scientists published a paper exploring the idea of ​​miniaturized nuclear reactors that power heavy torpedoes. While broadly ambitious, it underscores the broader, accelerating trend toward autonomous, self-organizing, high-endurance torpedo mines.

It seems that offensive mine warfare will play an important role in future conflicts. But tomorrow’s “mines” will be radically more dangerous than today’s. They will combine the endurance and range of conventional mines, the speed, lethality, and maneuverability of torpedoes, and the modularity, mobility, and autonomy of UUVs. But even if this convergence continues, our understanding of what constitutes a sea mine may need to change. Recent Ukrainian armed USV attacks on Russia’s Black Sea ports of Sevastopol and Novorossiysk suggest mobile “surface mines” could pose a uniquely dangerous threat to surface warships. We may soon find that offensive mine warfare is no longer confined to the underwater realm.

Avenger-class anti-mine ships USS Patriot (MCM 7) and USS Pioneer (MCM 9) conduct a mine warfare exercise. Pioneer, part of Mine Countermeasures Squadron 7, operates in the 7th Fleet area of ​​operations to improve interoperability with partners and to serve as a ready-to-play platform for contingency operations. (US Navy photo by Lt. jg Irving Garcia)